Finding a new book to read isn't always as simple as it sounds. After all, you have millions to choose from on any given topic, and Amazon's recommendation system only goes so far. BookRx is a webapp that scans your tweets and looks at who you follow to recommend books.

BookRx was built by students at Northwestern University's Knight Lab. The nice thing about BookRx is that it's not an app that connects into your Twitter account. Just enter your Twitter username (or a username of a friend if you're looking for gift ideas), and BookRx dishes out recommendations in a variety of different genres. Obviously the recommendations aren't 100% fool-proof, and you're not going to be interested in all the genres, but BookRx does at least get your search started. It could prove invaluable for any friends or family who you're still hunting for gifts for too. If you're just looking to get better recommendations for books in general, these five services should do the trick.